** Shares of Sunstone Metals STM.AX fall as much as 25% to
A$0.006, their biggest intraday pct loss since Sept 9
** The mineral explorer announces share repurchase plan to
raise A$4 mln ($2.69 mln) at an issue price of A$0.005 per share
** Says issue price at a discount of 37.5% to stock's last
close of A$0.008 on Oct 11
** Says funds will be used for mineral resource estimate in
an El Palmar copper-gold project in Ecuador, among others
** Over 22.5 mln shares change hands, 2.9x the 30-day avg of
7.7 mln
** Stock has lost 56.7% YTD, including current session's
moves
($1 = 1.4872 Australian dollars)
(Reporting by Kumar Tanishk in Bengaluru)
((Tanishk.Kumar@thomsonreuters.com;))